import java.util.ArrayList;

public class BicycleList
{
    //私有静态成员变量，存储唯一实例
    private static BicycleList instance = null;
    //在售电驴列表
    private ArrayList<Bicycle> list = null;

    //私有构造函数
    private BicycleList() {
        this.list = new ArrayList<Bicycle>();
    }

    //公有静态成员方法，返回唯一实例
    public static BicycleList GetBicycleList() {
        if (instance == null) {
            instance = new BicycleList();
        }
        return instance;
    }
    public void add(Bicycle bicycle) {
        list.add(bicycle);
    }
    public void display() {
        for (Bicycle bicycle : list)
            System.out.println(bicycle);
    }
}
